Currently, video surveillance storage devices require large amounts of media storage. Many hours of footage from a plurality of sources need to be stored for a certain amount of time before they are reviewed. For instance, a plurality of digital Closed-Circuit Television (CCTV) cameras may monitor different areas of a secure building such as a museum. The footage from each camera may be stored locally, or submitted to a control panel or further forwarded to a central monitoring station, at which point the video data will be stored on a database until it needs to be reviewed, or until it is expired.
Video data is stored for a number of reasons. If an incident, such as a theft, is detected, it is imperative to review at least the past couple of days of footage to detect patterns in the behavior of potential perpetrators. On the other hand, the reviewing of a certain video stream may be handed across multiple levels, where a junior officer reviews the video first, and then a more senior officer may review the footage. Since the process may take some time, the footage needs to be stored and accessible at any time (i.e., not archived).
Video data may also be erased for numerous reasons, the foremost of which is storage space. Digital video data is by no means compact. Even most compressed file formats occupy up to four times as much space as compressed audio, or 3-4 megabytes per minute. This number could go lower if video quality is sacrificed but a certain resolution needs to be maintained for effective security monitoring purposes. Since a couple of days of video and audio will require 3-4 gigabytes of storage space, one can predict how much of a burden on a storage unit it would be to have multiple cameras from different sources recording video that needs to be immediately accessible over a few days. Additionally, video data may also be erased for privacy concerns, depending on the footage and the age of the footage.
To prevent waste of valuable storage space and memory, storage devices may be programmed to “recycle” space automatically, at specified intervals, or based on certain factors. A logic unit on a storage server may be programmed to erase footage that is more than a week old. Alternatively, footage from different sources is prioritized differently, so low-priority footage is deleted to make room for higher-priority footage. The problem with this is that the “automation” is based on static pre-defined factors. Further, there is limited flexibility in defining these factors to determine optimal memory management. For instance, there is no ability to define recycling based user-selected events, user-bookmarked recordings for non-deletion, and user bookmarked recordings for deletion.
What is needed is the ability to efficiently and dynamically manage storage and memory in a surveillance system, thus ensuring maximum storage availability.